Maternal Complications and Facility‐Level Differences in the Management of Placental Abruption in Japan: A Retrospective Analysis Using a Multicenter DPC Database

OBJECTIVE: To evaluate maternal characteristics, management practices, and outcomes of placental abruption according to facility type in Japan, and to assess the effectiveness of the country's centralized perinatal care system. METHODS: This retrospective observational study used the Diagnosis Procedure Combination database from acute-care hospitals between May 2014 and April 2024. Cases coded with ICD-10 O45.0 or O45.9 were included, excluding those with multiple gestations or placenta previa. Patients were categorized into Comprehensive Perinatal Medical Centers (CPMCs) and Regional Perinatal Medical Centers/General Hospitals (non-CPMCs). The primary outcomes were severe and serious maternal complications as defined by Ananth et al. Secondary outcomes included mode of delivery, hysterectomy, transfusion use and volume, maternal and fetal mortality, intensive care unit admission, estimated blood loss at delivery, and length of hospital stay. RESULTS: Among 771 eligible cases, 257 (33.3%) were admitted to CPMCs and 514 (66.7%) to non-CPMCs. Referrals (78.2% vs. 68.5%) and ambulance transports (63.0% vs. 37.5%) were significantly more frequent in CPMCs. Severe maternal complications were more common in CPMCs (30.0% vs. 18.3%), particularly coagulopathy and hypovolemic shock, many of which were present at admission. Despite higher baseline severity, rates of serious maternal complications and maternal mortality did not differ. The mean length of hospital stay was shorter in CPMCs (6.0 vs. 6.7 days). CONCLUSION: Severe placental abruption cases appear to be effectively centralized within this multicenter cohort. The advanced maternal emergency capacity of CPMCs may mitigate morbidity despite higher baseline severity, supporting the functional role of perinatal regionalization within this network.